PIC12F675 trouble

[Archilochus]

Hi Russ,

EDIT - on this line of code...
BTFSS _leftCount ;23,us <- this line causes a problem it seems too.

You did not specify which BIT to test - it's also a WORD variable - maybe someone here can answer if BTFSS will work on a WORD??

OOpps - I thought the 12F's WERE 12-bit core - sorry!
EndEDIT

====

I have not looked over the rest - but here's a list of unsupported commands fort the 12bit cores:
from PBP 2.44 'new.txt' file

Commands that are not supported for the 12-bit core PICmicro MCUs:

Command Reason
Adcin No internal ADCs
Data No on-chip EEPROM
Dtmfout Not enough RAM or stack
Eeprom No on-chip EEPROM
Erasecode No flash devices
Freqout Not enough RAM or stack
Hpwm No hardware PWM
Hserin No hardware serial port
Hserin2 No hardware serial port
Hserout No hardware serial port
Hserout2 No hardware serial port
On Interrupt No Interrupts
Read No on-chip EEPROM
Readcode No flash devices
Resume No Interrupts
Serin2 Not enough RAM or stack
Serout2 Not enough RAM or stack
USBIn No USB devices
USBInit No USB devices
USBOut No USB devices
Write No on-chip EEPROM
Writecode No flash devices
Xin Not enough RAM or stack
Xout Not enough RAM or stack

[Darrel Taylor]

Hi Russ,

In the MainLoop, the IF (leftcount = duration) will never evaluate true.

duration is a constant(100), and leftcount never gets assigned anything but 0. Maybe you were thinking that BTFSS would do something, but that means "Bit Test File Skip if Set, so it's looking for a bit number that wasn't specified. Are you trying to test leftcount for a specific value, or trying to set the value?

Archilochus,

The 12F675's are actually 14-bit core's. I have no idea why they called them 12's. 12C508's are 12-bit, and the 12F508's are 12-bit, so you would think 12F629/675/683's are too. but, Not!
<br>

[Bruce]

btfss is for testing individual "bits" in a file register.

You would use btfss _leftCount,1 to test bit position 1 in leftCount. This
seems like an unnecessary test at any rate since you're clearing leftCount
at the entry point to your asm routine, and leftCount will always be zero.

Also be aware that you're only accessing the low bytes in your leftCount
and dur word variables the way you're when doing it.

To access the high byte in dur you would use decfsz _dur+1,f. Dur is a pointer
to the low byte. Adding _dur+1 moves the pointer to the next byte location
in ram.

[russman613]

awesome information - i love it when there is a simple answer.

thx for the tips and for pointing out my issue. i will try to fix up what you guys have pointed out this evening and retry. also looks like new.txt is worth a closer look.

any idea why the PIC seems to just hang? I would expect that it would at least toggle the statusLED for me that i've set up before it gets to a piece of bad code. or, am i to expect "unexpected" behavior anytime i muck up the logic anywhere in the program?

russ

[russman613]

awesome information - i love it when there is a simple answer. i had actually meant that line to read:

btfss gpio, 3;
incfsz _leftCount, 1 ;23,us - this line causes a problem it seems too.


thx for the tips and for pointing out my issue. i will try to fix up what you guys have pointed out this evening and retry. also looks like new.txt is worth a closer look.

any idea why the PIC seems to just hang? I would expect that it would at least toggle the statusLED for me that i've set up before it gets to a piece of bad code. or, am i to expect "unexpected" behavior anytime i muck up the logic anywhere in the program?

russ